A sub-con record identifies an operation that you are sub-contracting to an outside party to perform on your behalf. Any PARTs defined under the sub-con as well as all work up to the sub-con operation are free-issued to the chosen contractor along with a purchase order describing the work to be done. There can be any number of contractor choices to perform the operation. Unless you’ve specified otherwise, the planning system will choose the cheapest contractor when there are choices.

In the example above there are two choices on the Plating operation, one taking 5 days and the other 3 days. Unless the 5 day choice is cheaper, the planning system will choose the 3 day option because it's quicker.